With the proliferation of location-aware mobile devices in today's society, numerous location-based services have emerged. One such service is described in U.S. patent application Ser. No. 12/645,532, entitled FORMING CROWDS AND PROVIDING ACCESS TO CROWD DATA IN A MOBILE ENVIRONMENT, which was filed Dec. 23, 2009; U.S. patent application Ser. No. 12/645,539, entitled ANONYMOUS CROWD TRACKING, which was filed Dec. 23, 2009; U.S. patent application Ser. No. 12/645,535, entitled MAINTAINING A HISTORICAL RECORD OF ANONYMIZED USER PROFILE DATA BY LOCATION FOR USERS IN A MOBILE ENVIRONMENT, which was filed Dec. 23, 2009; U.S. patent application Ser. No. 12/645,546, entitled CROWD FORMATION FOR MOBILE DEVICE USERS, which was filed Dec. 23, 2009; U.S. patent application Ser. No. 12/645,556, entitled SERVING A REQUEST FOR DATA FROM A HISTORICAL RECORD OF ANONYMIZED USER PROFILE DATA IN A MOBILE ENVIRONMENT, which was filed Dec. 23, 2009; U.S. patent application Ser. No. 12/645,560, entitled HANDLING CROWD REQUESTS FOR LARGE GEOGRAPHIC AREAS, which was filed Dec. 23, 2009; and U.S. patent application Ser. No. 12/645,544, entitled MODIFYING A USER'S CONTRIBUTION TO AN AGGREGATE PROFILE BASED ON TIME BETWEEN LOCATION UPDATES AND EXTERNAL EVENTS, which was filed Dec. 23, 2009; all of which are hereby incorporated herein by reference in their entireties. Particularly, the aforementioned patent applications describe, among other things, a system and method for forming crowds of users. Specifically, the disclosed system and method utilize a spatial crowd formation process to form crowds of users based on the current locations of the users.
One issue with a purely spatial crowd formation process is that, depending on the particular technology utilized to obtain the current locations of the users, there may be a significant amount of error. For example, the error of a Global Positioning System (GPS) receiver may be up to 30 meters (m). This issue is further compounded when the users are indoors. Due to such errors, when venues or Points of Interest (POIs) are located relatively close to one another (e.g., stores in a shopping mall), it is often difficult to discern persons gathered in one POI from persons gathered in an adjacent or nearby POI. For example, if two POIs are separated only by a wall, then it is difficult to discern persons on one side of the wall from users on the other side of the wall. As a result, a purely spatial crowd formation process may fail to provide the desired accuracy. As such, there is a need for a system and method for forming crowds of users that provides delineation between users located at POIs that are relatively close to one another.